KABUL, Afghanistan --The Afghan soldier who killed a U.S. two-star general and wounded 15 other people hid in a bathroom with a NATO assault rifle then opened fire when a group of officers from international forces passed by, an Afghan military official said Wednesday.
As U.S. and Afghan officials investigated the attack Tuesday that killed, Maj. Gen. Harold J. Greene, the highest-ranked U.S. officer to be slain in combat since 1970 in the Vietnam War, authorities reported two other so-called "insider" attacks the same day.
In the deadliest of the attacks, an Afghan police officer killed seven of his colleagues at a checkpoint, then stole their weapons and fled in a police car late Tuesday in the Uruzgan provincial capital of Tirin Kot, provincial spokesman Doost Mohammad Nayab said.
A doctor at a local hospital told the AP it appeared the police officer drugged his colleagues before the shooting. The doctor spoke on condition of anonymity as he wasn't authorized to release the information. Nayab later denied that the police officers had been drugged and said the officer involved had Taliban connections, without elaborating.
In Paktia province, an Afghan police guard exchanged fire with NATO troops near the governor's office, provincial police said. The guard was killed in the gunfight.
Insider attacks in Afghanistan rose sharply in 2012, with more than 60 coalition troops - mostly Americans - killed in more than 40 attacks that threatened to shatter all trust between Afghan and allied forces. U.S. commanders imposed a series of precautionary tactics and the number of such attacks declined sharply last year.
Such attacks are sometimes claimed by the Taliban insurgency as proof of their infiltration. Others are attributed to personal disputes or resentment by Afghans who have soured on the continued international presence in their country more than a dozen years after the fall of the Taliban's ultra-conservative Islamic regime.
There has been no claim of responsibility in Tuesday's shooting that killed Greene and wounded at least 15 others, including a German general and two Afghan generals at Marshal Fahim National Defense University, west of the Afghan capital, Kabul.
The soldier who opened fire - and was subsequently killed in a shootout - was named Rafiqullah, was in his early 20s and joined the Afghan army more than two years ago, the Afghan military official said, speaking on condition of anonymity because he was not authorized to release the information. A second Afghan military official corroborated his account.
His motives were not immediately known, the officials said. He came from a district in Paktia province known to harbor fighters from the Haqqani network, which has strong links to the Taliban and conducts attacks against U.S. forces. There also were indications that Rafiqullah had a dispute with his own superiors before the shooting and opened fire because of it, said a U.S. official who spoke on condition of anonymity to discuss information not yet made public.
On Tuesday, Rafiqullah just had returned from a patrol around Camp Qargha, where the military school is located, the official said. Others on patrol with Rafiqullah turned in their NATO-issued assault rifles, but Rafiqullah kept his and hid in a bathroom. Rafiqullah opened fire when the generals walked into view, the official said.
About half of the wounded in Tuesday's attack at Marshal Fahim National Defense University were Americans, several of them reported to be in serious condition. However, there was no indication that Greene was specifically targeted.
In a statement, NATO said Greene's body was being prepared Wednesday to be flown to the U.S. via Dover Air Force Base in Delaware.
"Our thoughts and prayers are with Maj. Gen. Greene's family, and the families of our soldiers who were injured," NATO said. "These soldiers were professionals, committed to the mission."
U.S. Defense Secretary Chuck Hagel said the attack "is not going to affect our decision or resolve to continue moving forward on an enduring presence post-2014."
The German Defense Ministry identified its wounded officer Wednesday as Brig. Gen. Michael Bartscher, saying he was in stable condition at Baghram airfield and that authorities were considering bringing him back home.
Meanwhile, violence continued elsewhere in Afghanistan as Taliban fighters attacked a police checkpoint in Paktia province. Police killed nine Taliban fighters and wounded 10, while four officers were wounded, authorities said.
Associated Press writers Robert Burns in Washington; Lolita C. Baldor in Stuttgart, Germany; Mirwais Khan in Kandahar, Afghanistan; Kirsten Grieshaber in Berlin; Jon Gambrell in Cairo; and Rahim Faiez contributed to this report.